Chapter 4: Active Adults

Adults who are physically active are healthier and less likely to
develop many chronic diseases than adults who are inactive. They also have
better fitness, including a healthier body size and composition. These benefits
are gained by men and women and people of all races and ethnicities who have
been studied.

Adults gain most of these health benefits when they do the equivalent
of at least 150 minutes of moderate intensity aerobic physical activity (2
hours and 30 minutes) each week. Adults gain additional and more extensive
health and fitness benefits with even more physical activity.
Muscle-strengthening activities also provide health benefits and are an
important part of an adult's overall physical activity plan.

This chapter provides guidance for most men and women aged 18 to 64
years, and focuses on physical activity beyond baseline activity (the usual
light or sedentary activities of daily living). Physical activity guidelines
for women during pregnancy and the postpartum period and for adults with
disabilities and select chronic conditions are discussed in Chapter
7—Additional Considerations for Some Adults.

Aerobic Activity

Aerobic activities, also called endurance activities, are physical
activities in which people move their large muscles in a rhythmic manner for a
sustained period. Running, brisk walking, bicycling, playing basketball,
dancing, and swimming are all examples of aerobic activities. Aerobic activity
makes a person's heart beat more rapidly to meet the demands of the
body's movement. Over time, regular aerobic activity makes the heart and
cardiovascular system stronger and fitter.

The purpose of the aerobic activity does not affect whether it counts
toward meeting the Guidelines. For example, physically active occupations can
count toward meeting the Guidelines, as can active transportation choices
(walking or bicycling). All types of aerobic activities can count as long as
they are of sufficient intensity and duration. Time spent in muscle
strengthening activities does not count toward the aerobic activity guidelines.

When putting the Guidelines into action, it's important to
consider the total amount of activity, as well as how often to be active, for
how long, and at what intensity.

Key Guidelines for Adults

All adults should avoid inactivity. Some physical activity is
better than none, and adults who participate in any amount of physical activity
gain some health benefits.

For substantial health benefits, adults should do at least 150
minutes (2 hours and 30 minutes) a week of moderate-intensity, or 75 minutes (1
hour and 15 minutes) a week of vigorous-intensity aerobic physical activity, or
an equivalent combination of moderate- and vigorous-intensity aerobic activity.
Aerobic activity should be performed in episodes of at least 10 minutes, and
preferably, it should be spread throughout the week.

For additional and more extensive health benefits, adults should
increase their aerobic physical activity to 300 minutes (5 hours) a week of
moderate-intensity, or 150 minutes a week of vigorous-intensity aerobic
physical activity, or an equivalent combination of moderate- and
vigorous-intensity activity. Additional health benefits are gained by engaging
in physical activity beyond this amount.

Adults should also do muscle-strengthening activities that are
moderate or high intensity and involve all major muscle groups on 2 or more
days a week, as these activities provide additional health benefits.

How Much Total Activity a Week?
When adults do the
equivalent of 150 minutes of moderate-intensity aerobic activity each week, the
benefits are substantial. These benefits include lower risk of
premature death, coronary heart disease, stroke, hypertension, type 2 diabetes,
and depression.

Not all health benefits of physical activity occur at 150 minutes a
week. As a person moves from 150 minutes a week toward 300 minutes (5 hours) a
week, he or she gains additional health benefits. Additional benefits
include lower risk of colon and breast cancer and prevention of unhealthy
weight gain.

Also, as a person moves from 150 minutes a week toward 300 minutes a
week, the benefits that occur at 150 minutes a week become more
extensive. For example, a person who does 300 minutes a week has an even
lower risk of heart disease or diabetes than a person who does 150 minutes a
week.

The benefits continue to increase when a person does more than the
equivalent of 300 minutes a week of moderate-intensity aerobic activity. For
example, a person who does 420 minutes (7 hours) a week has an even lower risk
of premature death than a person who does 150 to 300 minutes a week. Current
science does not allow identifying an upper limit of total activity above which
there are no additional health benefits.

How Many Days a Week and for How Long?
Aerobic
physical activity should preferably be spread throughout the week. Research
studies consistently show that activity performed on at least 3 days a week
produces health benefits. Spreading physical activity across at least 3 days a
week may help to reduce the risk of injury and avoid excessive fatigue.

Both moderate- and vigorous-intensity aerobic activity should be
performed in episodes of at least 10 minutes. Episodes of this duration are
known to improve cardiovascular fitness and some risk factors for heart disease
and type 2 diabetes.

How Intense?
The Guidelines for adults focus on two
levels of intensity: moderate-intensity activity and vigorous–intensity
activity. To meet the Guidelines, adults can do either moderate-intensity or
vigorous-intensity aerobic activities, or a combination of both. It takes less
time to get the same benefit from vigorous-intensity activities as from
moderate-intensity activities. A general rule of thumb is that 2 minutes of
moderate-intensity activity counts the same as 1 minute of vigorous-intensity
activity. For example, 30 minutes of moderate-intensity activity a week is
roughly the same as 15 minutes of vigorous-intensity activity.

There are two ways to track the intensity of aerobic activity: absolute
intensity and relative intensity.

Absolute intensity is the amount of energy expended
per minute of activity. The energy expenditure of light-intensity activity, for
example, is 1.1 to 2.9 times the amount of energy expended when a person is at
rest. Moderate-intensity activities expend 3.0 to 5.9 times the amount of
energy expended at rest. The energy expenditure of vigorous-intensity
activities is 6.0 or more times the energy expended at rest.

Relative intensity is the level of effort required
to do an activity. Less fit people generally require a higher level of effort
than fitter people to do the same activity. Relative intensity can be estimated
using a scale of 0 to 10, where sitting is 0 and the highest level of effort
possible is 10. Moderate intensity activity is a 5 or 6. Vigorous-intensity
activity is a 7 or 8.

For More Information

See Appendix 1 for more information on using absolute or relative
intensity

The Guidelines for adults refer to absolute intensity because most
studies demonstrating lower risks of clinical events (for example, premature
death, cardiovascular disease, type 2 diabetes, cancer) have focused on
measuring absolute intensity. That is, the Guidelines are based on the absolute
amount of energy expended in physical activity that is associated with health
benefits. The table lists some examples of activities classified as
moderate-intensity or vigorous intensity based on absolute intensity. Either
absolute or relative intensity can be used to monitor progress in meeting the
Guidelines.

When using relative intensity, people pay attention to how physical
activity affects their heart rate and breathing. As a rule of thumb, a person
doing moderate-intensity aerobic activity can talk, but not sing, during the
activity. A person doing vigorous intensity activity cannot say more than a few
words without pausing for a breath.

Note: This table provides several examples of
activities classified as moderate-intensity or vigorous-intensity, based on
absolute intensity. This list is not all-inclusive. Instead, the examples are
meant to help people make choices.

Muscle-Strengthening Activity

Muscle-strengthening activities provide additional benefits not found
with aerobic activity. The benefits of muscle-strengthening activity include
increased bone strength and muscular fitness. Muscle-strengthening activities
can also help maintain muscle mass during a program of weight loss.

Muscle-strengthening activities make muscles do more work than they are
accustomed to doing. That is, they overload the muscles. Resistance training,
including weight training, is a familiar example of muscle-strengthening
activity. Other examples include working with resistance bands, doing
calisthenics that use body weight for resistance (such as push-ups, pull-ups,
and sit-ups), carrying heavy loads, and heavy gardening (such as digging or
hoeing).

Muscle-strengthening activities count if they involve a moderate to
high level of intensity or effort and work the major muscle groups of the body:
the legs, hips, back, chest, abdomen, shoulders, and arms. muscle strengthening
activities for all the major muscle groups should be done at least 2 days a
week.

No specific amount of time is recommended for muscle strengthening, but
muscle-strengthening exercises should be performed to the point at which it
would be difficult to do another repetition without help. When resistance
training is used to enhance muscle strength, one set of 8 to 12 repetitions of
each exercise is effective, although two or three sets may be more effective.
Development of muscle strength and endurance is progressive over time.
Increases in the amount of weight or the days a week of exercising will result
in stronger muscles.

Meeting the Guidelines

Adults have many options for becoming physically active, increasing
their physical activity, and staying active throughout their lives. In deciding
how to meet the Guidelines, adults should think about how much physical
activity they're already doing and how physically fit they are. Personal
health and fitness goals are also important to consider. Examples provided
later in the chapter illustrate how to include these goals in decisions to be
active.

In general, healthy men and women who plan prudent increases in their
weekly amounts of physical activity do not need to consult a health-care
provider before becoming active.

Inactive Adults

Inactive adults or those who don't yet do 150 minutes of physical
activity a week should work gradually toward this goal. The initial amount of
activity should be at a light or moderate intensity, for short periods of time,
with the sessions spread throughout the week. The good news is that "some
is better than none."

People gain some health benefits even when they do as little as 60
minutes a week of moderate-intensity aerobic physical activity.

To reduce risk of injury, it is important to increase the amount of
physical activity gradually over a period of weeks to months. For example, an
inactive person could start with a walking program consisting of 5 minutes of
slow walking several times each day, 5 to 6 days a week. The length of time
could then gradually be increased to 10 minutes per session, 3 times a day, and
the walking speed could be increased slowly.

Muscle-strengthening activities should also be gradually increased over
time. Initially, these activities can be done just 1 day a week starting at a
light or moderate level of effort. Over time, the number of days a week can be
increased to 2, and then possibly to more than 2. Each week, the level of
effort (intensity) can be increased slightly until it becomes moderate to high.

Active Adults

Adults who are already active and meet the minimum Guidelines (the
equivalent of 150 minutes of moderate-intensity aerobic activity every week)
can gain additional and more extensive health and fitness benefits by
increasing physical activity above this amount. Most American adults should
increase their aerobic activity to exceed the minimum level and move toward 300
minutes a week. Adults should also do muscle-strengthening activities on at
least 2 days each week.

One time-efficient way to achieve greater fitness and health goals is
to substitute vigorous-intensity aerobic activity for some moderate-intensity
activity. Using the 2-to-1 rule of thumb, doing 150 minutes of
vigorous-intensity aerobic activity a week provides about the same benefits as
300 minutes of moderate intensity activity.

Adults are encouraged to do a variety of activities, as variety
probably reduces risk of injury caused by doing too much of one kind of
activity (this is called an overuse injury).

Highly Active Adults

Adults who are highly active should maintain their activity level.
These adults are also encouraged to do a variety of activities.

Special Considerations

Flexibility Activities

Flexibility is an important part of physical fitness. Some types of
physical activity, such as dancing, require more flexibility than others.
Stretching exercises are effective in increasing flexibility, and thereby can
allow people to more easily do activities that require greater flexibility. For
this reason, flexibility activities are an appropriate part of a physical
activity program, even though they have no known health benefits and it is
unclear whether they reduce risk of injury. Time spent doing flexibility
activities by themselves does not count toward meeting the aerobic or
muscle-strengthening Guidelines.

Warm-up and Cool-down

Warm-up and cool-down activities are an acceptable part of a
person's physical activity plan. Commonly, the warm-up and cool-down
involve doing an activity at a slower speed or lower intensity. A warm-up
before moderate- or vigorous-intensity aerobic activity allows a gradual
increase in heart rate and breathing at the start of the episode of activity. A
cool-down after activity allows a gradual decrease at the end of the episode.
Time spent doing warm-up and cool-down may count toward meeting the aerobic
activity Guidelines if the activity is at least moderate intensity (for
example, walking briskly as a warm-up before jogging). A warm-up for
muscle-strengthening activity commonly involves doing exercises with lighter
weight.

For More Information

See the Dietary Guidelines for Americans for additional
information on weight management and how to determine a healthy weight.

Physical Activity in a Weight-Control Plan

Along with appropriate dietary intake, physical activity is an
important part of maintaining healthy weight, losing weight, and keeping extra
weight off once it has been lost. Physical activity also helps reduce abdominal
fat and preserve muscle during weight loss. Adults should aim for a healthy,
stable body weight. The amount of physical activity necessary to achieve this
weight varies greatly from person to person.

The first step in achieving or maintaining a healthy weight is to meet
the minimum level of physical activity in the Guidelines. For some people this
will result in a stable and healthy body weight, but for many it may not.

The health benefits of physical activity are generally independent of
body weight. The good news for people needing to lose weight is that regular
physical activity provides major health benefits, no matter how their weight
changes over time.

Adults should strongly consider walking as one good way to get aerobic
physical activity. Many studies show that walking has health benefits and a low
risk of injury. It can be done year-round and in many settings.

People who are at a healthy body weight but slowly gaining weight can
either gradually increase the level of physical activity (toward the equivalent
of 300 minutes a week of moderate-intensity aerobic activity), or reduce
caloric intake, or both, until their weight is stable. By regularly checking
body weight, people can find the amount of physical activity that works for
them.

Many adults will need to do more than the 150 minutes a week of
moderate-intensity aerobic physical activity as part of a program to lose
weight or keep it off. These adults should do more physical activity and/or
further reduce their caloric intake. Some people will need to do the equivalent
of 300 or more minutes of moderate-intensity physical activity a week to meet
their weight-control goals. Combined with restricting caloric intake, these
adults should gradually increase minutes or the intensity of aerobic physical
activity per week, to the point at which the physical activity is effective in
achieving a healthy weight.

It is important to remember that all activities—both baseline and
physical activity—"count" for energy balance. Active choices,
such as taking the stairs rather than the elevator or adding short episodes of
walking to the day, are examples of activities that can be helpful in weight
control.

For weight control, vigorous-intensity activity is far more
time-efficient than moderate-intensity activity. For example, an adult who
weighs 165 pounds (75 kg) will burn 560 calories from 150 minutes of brisk
walking at 4 miles an hour (these calories are in addition to the calories
normally burned by a body at rest). That person can burn the same number of
additional calories in 50 minutes by running 5 miles at a 10 minutes-per-mile
pace.

Getting and Staying Active: Real-Life Examples

Adults can meet the Physical Activity Guidelines in all sorts
of ways and with many types of physical activity. The choices of types and
amounts of physical activity depend on personal health and fitness goals. Here
are three examples.

Jean: An Inactive Middle-Aged Woman

Her goals: Jean sets a goal of doing 1 hour a day of
moderate-intensity aerobic activity on 5 days a week (a total of 300 minutes a
week). Weighing 220 pounds, Jean is obese and wants to lose about 1 pound of
weight each week.

Starting out: Jean cuts back on her caloric intake and
starts walking 5 minutes in the morning and 5 minutes in the evening most days
of the week. She walks at a 2.5 mile-an-hour pace. Although physical activity
tables show this to be light-intensity activity, for her level of fitness and
fatness, it is appropriate moderate–intensity activity.

Making good progress: Two months later, Jean is
comfortably walking 30 to 40 minutes at moderate intensity to and from her bus
stop every day. She then adds variety to her activity by alternating among
walking, riding a stationary cycle, and low-impact aerobics. She also begins
muscle-strengthening activities, using elastic bands twice each week.

Adults can meet the Physical Activity Guidelines in all sorts
of ways and with many types of physical activity.

Reaching her goal: Eventually, Jean works up to 300
minutes a week of moderate-intensity aerobic activity, including her brisk
walks to and from the bus stop. She has lost 40 pounds of weight in 1 year,
with most of the weight loss occurring the previous 6 months when she mastered
her diet and was able to do greater amounts of physical activity.

Douglas: An Active Middle-Aged Man

His goal and current activity pattern: Douglas was a
soccer player in his youth. His goal is to get back into shape by becoming a
regular recreational runner. In addition to his job operating heavy equipment,
he walks 30 to 40 minutes a day on 5 days each week. He also lifts weights 2
days a week.

Starting out: Douglas starts a walk/jog program with
a co-worker and plans to gradually replace walking with jogging and then
running. The first week he goes out on 5 days, walking for 25 minutes and
jogging for 5 minutes.

Making good progress: Each week, Douglas gradually
increases the time spent jogging (vigorous-intensity activity) and reduces the
time spent walking (moderate–intensity activity). He also continues his
weight-lifting program.

Reaching his goal: Eventually, Douglas is running 30
to 45 minutes 4 days a week and lifting weights 2 days a week. He goes for a
1-hour bicycle ride on most weekends.

Anita: A Very Active College-Aged Adult

Her goals and current activity pattern: Anita plays
league basketball (vigorous-intensity activity) 4 days each week for 90 minutes
each day. She wants to reduce her risk of injury from doing too much of one
kind of activity (this is called an overuse injury).

Starting out: Anita starts out by cutting back her
basketball playing to 3 days each week. She begins to bicycle to and from
campus (30 minutes each way) instead of driving her car. She also joins a yoga
class that meets twice each week.

Reaching her goal: Eventually, Anita is bicycling 3
days each week to and from campus in addition to playing basketball. Her yoga
class helps her to build and maintain strength and flexibility.

Achieving Target Levels of Physical Activity: The Possibilities Are
Endless

These examples show how it's possible to meet the Guidelines by
doing moderate-intensity or vigorous-intensity activity or a combination of
both. Physical activity at this level provides substantial health benefits.

Ways to get the equivalent of 150 minutes (2 hours and 30 minutes) of
moderate-intensity aerobic physical activity a week plus muscle-strengthening
activities:

Thirty minutes of biking to and from work on 3 days (moderate
intensity), playing softball for 60 minutes on 1 day (moderate intensity),
using weight machines on 2 days (muscle-strengthening on 2 days); and

Forty-five minutes of doubles tennis on 2 days (moderate
intensity), lifting weights after work on 1 day (muscle strengthening), hiking
vigorously for 30 minutes and rock climbing (muscle strengthening) on 1 day.

Ways to be even more active

For adults who are already doing at least 150 minutes of
moderate-intensity physical activity, here are a few ways to do even more.
Physical activity at this level has even greater health benefits.

Forty-five minutes of brisk walking every day, exercising with
resistance bands on 2 or 3 days;

Forty-five minutes of running on 3 or 4 days, circuit weight
training in a gym on 2 or 3 days;

Thirty minutes of running on 2 days, 45 minutes of brisk walking
on 1 day, 45 minutes of an aerobics and weights class on 1 day, 90 minutes (1
hour and 30 minutes) of social dancing on 1 evening, 30 minutes of mowing the
lawn, plus some heavy garden work on 1 day;

Ninety minutes of playing soccer on 1 day, brisk walking for 15
minutes on 3 days, lifting weights on 2 days; and